Dynamic routing is fascinating, but also potentially frustrating for the rider. Your trip to work could take 10 minutes, or it could take 30 minutes, depending on who else wants to ride at the same time and how "dynamic" your bus routing gets. With a scheduled service, at least you know when the bus will show up. Of course, if it only runs once an hour and not at the time you want, you may still opt for the "flexible" option, but it's not guaranteed to be a win in all cases.